The majority of a collection — in most cases — is in storage rather than on display at any given time. How unframed prints are stored is therefore one of the most consequential decisions a collector makes, and also one of the most frequently neglected. Poor storage conditions can cause more damage than poor display, because the consequences are not visible until significant deterioration has already occurred.
The Basic Requirements
Prints in storage need stable temperature and humidity, darkness, clean air, and protection from physical contact with unsuitable materials. The ideal storage environment is cool (around 65°F / 18°C or lower), at 40–50% relative humidity, and away from any light source. A climate-controlled room or a dedicated storage cabinet in a temperature-stable interior space is appropriate. Attics, basements, and garages — environments with extreme temperature swings and humidity variation — are strongly contraindicated.
Archival Enclosures
Each print should be stored in its own archival enclosure — either a polyester sleeve (Mylar or equivalent) or an acid-free glassine interleaving sheet. Polyester sleeves allow the print to be viewed without handling, reducing the risk of fingerprint oils and abrasion damage. Glassine is less expensive and appropriate for prints that will be handled less frequently. Do not use PVC sleeves — PVC releases plasticizers over time that can damage photographic materials.
Flat Files and Archival Boxes
Flat files — horizontal drawer systems designed for storing maps and architectural drawings — are the professional standard for storing unframed prints flat. They provide support across the entire print surface, prevent bending, and keep prints in darkness. A good flat file is a significant investment but pays for itself in the protection it provides to a valuable collection.
For collectors without flat files, archival clamshell boxes designed for print storage are an excellent alternative. They are available in standard fine art print sizes and can be stored on shelves. Prints should be stored flat or very nearly so — vertical storage causes prints to sag and can lead to permanent creasing or deformation over time, especially in humid environments.
Interleaving
When multiple prints are stored together, they must be separated by interleaving material — archival tissue or glassine between each print. Prints stored in direct contact can transfer surface chemistry to each other, abrade each other’s surfaces, and in humid conditions can stick together with potentially catastrophic results. This applies even to prints in individual sleeves if the sleeves are stored in a stack — weight and pressure over time can cause transfer through the sleeve material.
Labeling and Access
Label storage boxes clearly on the outside — edition title, photographer, date, and condition notes. Maintain an inventory that matches the labels. When accessing stored prints, handle them by the edges only, with clean dry hands or cotton gloves. Lay them flat on a clean, dry surface for examination. Return them to their enclosures before attending to anything else.